Bags made of thin polyethylene material have been used in various sizes. Small bags are used in packaging of sandwiches and the like. Larger bags are used as shopping bags. Even large bags are used for containing trash.
A particularly advantageous closure for such a bag includes a draw tape constructed from the same polyethylene material. U.S. Pat. No. 3,029,853--Piazzi, and British Pat. No. 1,125,363--Jortikka are examples of draw tape bags. Such closures have been successfully employed on these bags.
Draw tape closures for large trash bags, and the manufacture of these draw tape trash bags, are described in the related applications identified below.
In the past, thermoplastic bag structures with handle elements have been produced by a method which reduces stress concentration. Stress points around the bag mouth are distributed to areas which are less likely to rupture as a result of stress concentration. See U.S. Pat. No. 4,165,832--Kuklies, et al. This patent discloses a thermoplastic bag structure with integral handle elements and stress relief notches positioned at opposite ends of the mouth.
Previous handle configurations for thermoplastic bags have been characterized by exhibiting the effect of "roping" while the bag is under load. According to the Kuklies, et al patent, stress concentration causes a thermoplastic handle to form a rope while under load, such rope having a diameter given by: EQU D=(8WG/.pi.)1/2
where D is the diameter, W is the width of the handle structure, and G is the gauge, in mils, of the structure.
A decrease in the gauge of a thermoplastic handle exhibiting the above characteristic would give a rope of a decreased diameter. A thermoplastic bag handle forming a rope of a smaller diameter will cause more discomfort to the carrier of such a bag, due to a decreased area of distribution of the weight of the bag upon the hand of the carrier.
It is desirable to produce a thermoplastic bag handle of a smaller gauge, less costly material, without decreasing the diameter of the rope which such a handle will form while under load.